(c) If slump is still not within specifications, refer problem to mix designer.
(a) Place slump cone (fig. 2-42) on a flat level surface and moisten the cone.
(b) Set all controls to the settings as calculated for the mix design using a water setting halfway between
the normal sand and dry sand settings.
(c) Prepare vehicle for concrete production.
(3) Conduct Test.
(a) Begin concrete production and waste the initial production (approximately a shovel full) until a
stabilized, uniform concrete mix Is being produced, then swing the mix conveyor for discharge into a
wheelbarrow. Fill the wheelbarrow with mixed concrete.
(b) Fill slump cone one-third full from wheelbarrow.
(c) Using rounded end of steel rod, rod concrete 25 strokes.
(d) Add concrete to the slump cone until it is two-thirds full.
(e) Rod concrete 25 strokes. Rod must penetrate second layer with each stroke.
(f) Add concrete to fill the slump cone.
(g) Rod 25 strokes. Rod must penetrate second layer with each stroke. Concrete must be level with top
of cone when rodding is completed.
(h) Carefully remove the cone by lifting it straight up.
(i) Place the slump cone next to the cone of concrete.
(j) Place the one end of the steel rod on top of slump cone with the other end over the cone of concrete
(k) Using a ruler measure the difference in height between the top of the slump cone and the top of the
cone of concrete. This difference (in inches) is the slump. For general concrete construction this
slump is three inches.
(I) If slump is not within mix design specifications slightly decrease or increase the water setting,
however, never decrease the setting below the normal sand setting nor increase the setting above the
dry sand setting and recheck slump. To increase slump increase water, to de- crease slump